Computer device and cluster server device

ABSTRACT

A computer device includes a plurality of information processing units configured to execute respective information processing functions, a plurality of storage units, one of which is arranged in each of the information processing units, and which are removable, a plurality of storage devices physically dispersed in the storage units, and having a redundant configuration, where one storage unit includes at least two storage devices, and a plurality of controllers configured to be installed in the information processing units, and to access the storage devices, where each information processing unit includes one of the controllers.

This application is a continuing application, filed under 35 U.S.C.§111(a), of International Application PCT/JP2003/010343, filed Aug. 14,2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a computer device and a cluster serverdevice that can hot-swap a storage device having a redundantconfiguration, in a plurality of information processing units.

2. Description of the Related Art

FIG. 9 is a perspective view of an external configuration of aconventional computer device 10. The computer device 10 is, for example,a server device including a central processing unit (CPU) (not shown), ahard disk controller (HDD), and the like, provided inside a casing 11.

Two slots 12 ₁ and 12 ₂ are formed in a front face of the casing 11.Hard disks (HDD) 13 ₁ and 13 ₂ are removably inserted into the slots 12₁ and 12 ₂.

The HDD controller controls writing to and reading from the HDDs 13 ₁and 13 ₂, which are large-capacity storage devices that store varioustypes of data handled by the CPU. The HDDs 13 ₁ and 13 ₂ are arranged ina redundant configuration.

A mirror ring is used to store identical data in the HDDS 13 ₁ and 13 ₂,so that one can be used for recovery if the other breaks down.

The computer device 10 also includes a function of, when one of the HDDs13 ₁ and 13 ₂ breaks down, replacing the broken HDD without terminatingthe operation of the computer device 10 (hot-swap).

If the HDD 13 ₁ breaks down, data is recovered from the HDD 13 ₂. Thebroken HDD 13 ₁ is removed from the slot 12 ₁ without terminating theoperation of the computer device 10, and a replacement HDD (not shown)is inserted into the slot 12 ₁.

Japanese Patent Application Laid-Open No. H11-184643 discloses aconventional computer device. FIG. 10 is a perspective view of anexternal configuration of a conventional computer device 20. Thecomputer device 20 is a cluster server device (blade server device) inwhich a plurality of card-type information processing units 30 ₁ to 30_(n) can be inserted into a casing 21. Each of the informationprocessing units 30 ₁ to 30 _(n) has the same functions as the computerdevice 10 (see FIG. 9).

‘n’ number of slots 22 ₁ to 22 _(n) are formed in a front face of thecasing 21. The information processing units 30 ₁ to 30 _(n) areremovably inserted into the slots 22 ₁ to 22 _(n).

FIG. 11 is a cross section taken along line X-X′ of FIG. 10. In FIG. 11,like reference numerals designate like parts as those shown in FIG. 10.In FIG. 11, a back plane 23 is provided inside the casing 21, and isphysically and electrically connected to the information processingunits 30 ₁ to 30 _(n) (see FIG. 10). The back plane 23 supplieselectrical power to the information processing units 30 ₁ to 30 _(n),and has a function of providing an interface.

The information processing unit 30 ₁ consists of a card-shaped printedcircuit board 31 ₁, an HDD 32A₁, an HDD 32B₁, a CPU 33 ₁, and an HDDcontroller 34 ₁, and includes the same server functions as the computerdevice 10, as mentioned already.

The HDD 32A₁, the HDD 32B₁, the CPU 33 ₁, and the HDD controller 34 ₁are mounted on the printed circuit board 31 ₁. The informationprocessing unit 30 ₁ is mounted on the back plane 23 via a connector 35₁.

The HDD controller 34 ₁ controls writing to and reading from the HDD32A₁ and the HDD 32B₁, which are large-capacity storage devices thatstore various types of data handled by the CPU 33 ₁. The HDD 32A₁ andthe HDD 32B₁ are arranged in a redundant configuration.

A mirror ring is used to store identical data in the HDDs 32A₁ and 32B₁,so that one can be used for recovery if the other breaks down.Therefore, if the HDD 32A₁ breaks down, data is recovered from the HDD32B₁.

In the conventional computer device 20 (FIGS. 10 and 11), the HDD 32A₁and the HDD 32B₁ in the information processing unit 30 ₁ shown in FIG.11 have a redundant configuration. However, although data can berecovered from one of the HDDs if the other breaks down, there is aproblem that the broken HDD cannot be hot-swapped.

The HDD 32A₁ and the HDD 32B₁ are mounted on the same printed circuitboard 31 ₁, and to replace the broken HDD 32A₁, the entire printedcircuit board 31 ₁ must be removed from the back plane 23, and theoperation of the information processing unit 30 ₁ (server) must beterminated while the broken HDD 32A₁ is replaced with a replacement HDD.The information processing unit 30 ₁ must then be remounted on the backplane 23.

SUMMARY OF THE INVENTION

It is an object of the present invention to at least solve the problemsin the conventional technology.

According to an aspect of the present invention, a computer deviceincludes a plurality of information processing units configured toexecute respective information processing functions; a plurality ofstorage devices configured to be mounted in the information processingunits in a physically dispersed manner, and configured to have aredundant configuration; and a controller configured to access thestorage devices.

According to another aspect of the present invention, a computer deviceincludes a plurality of information processing units configured toexecute respective information processing functions; a plurality ofstorage units configured to form a part of the information processingunits, and configured to be removably mounted therein; a plurality ofstorage devices configured to be mounted in the storage units in aphysically dispersed manner, and configured to have a redundantconfiguration, where one storage unit includes at least two storagedevices; and a plurality of controllers configured to be mounted in theinformation processing units and to access the storage devices, whereeach information processing unit includes one of the controllers.According to still another aspect of the present invention, a clusterserver device includes a plurality of information processing units, eachincluding a server function; a plurality of storage devices configuredto be mounted in the information processing units in a physicallydispersed manner, and configured to have a redundant configuration; anda controller configured to access the storage devices.

According to still another aspect of the present invention, a clusterserver device includes a plurality of information processing units, eachincluding a server function; a plurality of storage units configured toform a part of the information processing units, and configured to beremovably mounted therein; a plurality of storage devices configured tobe mounted in the storage units in a physically dispersed manner, andconfigured to have a redundant configuration; and a plurality ofcontrollers configured to be respectively mounted in the informationprocessing units, and to access the storage devices, where eachinformation processing unit includes one of the controllers.

The above objects, features, advantages and technical and industrialsignificance of this invention will be better understood by reading thefollowing detailed description of presently preferred embodiments of theinvention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of a configuration of a computer deviceaccording to a first embodiment of the present invention;

FIG. 2 is a cross section taken along line Y-Y′ of FIG. 1;

FIG. 3 is a diagram to explain a hot-swap method according to the firstembodiment;

FIG. 4 is another diagram to explain the hot-swap method according tothe first embodiment;

FIG. 5 is still another diagram to explain the hot-swap method accordingto the first embodiment;

FIG. 6 is a schematic plan view of a configuration of a computer deviceaccording to a second embodiment;

FIG. 7 is a diagram to explain a hot-swap method according to the secondembodiment;

FIG. 8 is another diagram to explain the hot-swap method according tothe second embodiment;

FIG. 9 is a perspective view of an external configuration of aconventional computer device;

FIG. 10 is a perspective view of the external configuration of aconventional computer device; and

FIG. 11 is a cross section taken along line X-X′ of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention will be explained indetail below with reference to the accompanying drawings.

FIG. 1 is a schematic plan view of a configuration of a computer deviceaccording to a first embodiment of the present invention. FIG. 2 is across section taken along line Y-Y′ of FIG. 1. In FIGS. 1 and 2, likereference numerals designate like parts as those shown in FIGS. 10 and11.

A computer device 40 shown in FIG. 1 is a cluster server device (bladeserver device) in which a plurality of information processing units 50₁, 50 ₂, 50 ₃, . . . can be provided in the casing 21.

In FIG. 1, although the information processing units 50 ₁, 50 ₂, 50 ₃, .. . are provided vertically in the same manner as the informationprocessing units 30 ₁, 30 ₂, . . . shown in FIG. 10, they are depictedin a plan view in the drawing.

The information processing units 50 ₁, 50 ₂, 50 ₃, . . . can be freelyinserted into and removed from slots 22 ₁, 22 ₂, 22 ₃, . . . in thecasing 21.

A back plane 41 is provided inside the casing 21, and is physically andelectrically connected to the information processing units 50 ₁, 50 ₂, .. . via connectors 57 ₁, 57 ₂, . . . (see FIG. 2). The back plane 41supplies electrical power to the information processing units 50 ₁, 50₂, 50 ₃, . . . , and provides an interface.

Each of the information processing units 50 ₁, 50 ₂, 50 ₃, . . .includes a server function similar to that of the computer device 10(see FIG. 9).

Two of the information processing units 50 ₁, 50 ₂, 50 ₃, . . . form oneset. In FIG. 1, the information processing units 50 ₁ and 50 ₂ form oneset.

The information processing unit 50 ₁ includes a storage unit 51 ₁ and aprocessor unit 54 ₁. The storage unit 51 ₁ and the processor unit 54 ₁can be freely mounted and removed via a connector 53 ₁. The storage unit51 ₁ includes an HDD 52A₁ and an HDD 52B₁ that are mounted on the samecircuit board. The processor unit 54 ₁ includes a CPU 55A₁ and an HDDcontroller 56A₁ that are mounted on the same circuit board.

The information processing unit 50 ₂ includes a storage unit 51 ₂ and aprocessor unit 54 ₂. The storage unit 51 ₂ and the processor unit 54 ₂can be freely mounted and removed via a connector 53 ₂. The storage unit51 ₂ includes an HDD 52A₂ and an HDD 52B₂ that are mounted on the samecircuit board. The processor unit 54 ₂ includes a CPU 55B₂ and an HDDcontroller 56B₂ that are mounted on the same circuit board.

In the information processing units 50 ₁ and 50 ₂, componentsrepresented by (A) in FIG. 1 (the HDD 52A₁, the HDD 52A₂, the CPU 55A₁,and the HDD controller 56A₁) form a group A. This group A corresponds toone computer device 10 (see FIG. 9) having a redundant configurationconsisting of two HDDs.

In group A, the HDD controller 56A₁ controls writing to and reading fromthe HDD 52A₁ and the HDD 52A₂, which are large-capacity storage devicesthat store various types of data handled by the CPU 55A₁.

The HDD 52A₁ is connected to the HDD controller 56A₁ via the connector53 ₁. The HDD 52A₂ is connected to the HDD controller 56A₁ via theconnector 53 ₁, the processor unit 54 ₂, the connector 57 ₂, the backplane 41, and the connector 57 ₁.

The HDD 52A₁ and the HDD 52A₂ are mounted by dispersion in physicallyseparate storage units (the storage units 51 ₁ and 51 ₂).

Components represented by (B) in FIG. 1 (the HDD 52B₁, the HDD 52B₂, theCPU 55B₂, and the HDD controller 56B₂) form a group B. This group Bcorresponds to one computer device 10 (see FIG. 9) having a redundantconfiguration consisting of two HDDs.

In group B, the HDD controller 56B₂ controls writing to and reading fromthe HDD 52B₁ and the HDD 52B₂, which are large-capacity storage devicesthat store various types of data handled by the CPU 55B₂.

The HDD 52B₁ is connected to the HDD controller 56B₂ via the connector53 ₁, the processor unit 54 ₁, the connector 57 ₁, the back plane 41,and the connector 57 ₂. The HDD 52B₂ is connected to the HDD controller56B₂ via the connector 53 ₂.

The HDD 52B₁ and the HDD 52B₂ are mounted by dispersion in physicallyseparate storage units (the storage units 51 ₁ and 51 ₂).

A hot-swap method according to the first embodiment will be explainedwith reference to FIGS. 3 to 5. An example in which the HDD 52A₂ breaksdown and is hot-swapped without terminating the operation of theinformation processing units 50 ₁ and 50 ₂ will be explained withreference to FIG. 3.

In FIG. 3, when the HDD 52A₂ of the storage unit 51 ₂ in group A breaksdown, data is recovered from the other HDD 52A₁ having the redundantconfiguration, thereby enabling continuous operation.

Due to the breakdown of the HDD 52A₂, the redundant configuration cannotbe utilized in group A, and therefore the HDD 52A₂ is hot-swapped. Asshown in FIG. 4, the storage unit 51 ₂ is removed as a whole andseparated from the processor unit 54 ₂.

In group A, the HDD 52A₁ is currently used and is accessed by the CPU55A₁ and the HDD controller 56A₁, whereby operation continues withoutbeing affected by the hot-swap.

Similarly in group B, the HDD 52B₁ is currently used and is accessed bythe CPU 55B₂ and the HDD controller 56B₂, whereby operation continueswithout being affected by the hot-swap.

In the disconnected storage unit 51 ₂, the broken HDD 52A₂ is replacedwith a replacement HDD 52A₂′.

As shown in FIG. 5, after this replacement, the storage unit 51 ₂ ismounted on the processor unit 54 ₂ via the connector 53 ₂. This restoresthe computer device 40 to its original state before breakdown.

As described above, according to the first embodiment, the HDDs 52A₁ and52A₂ (storage devices) having a redundant configuration are mounted byphysical dispersion, in a plurality of freely removable storage units 51₁ and 51 ₂ that form a part of the information processing units 50 ₁ and50 ₂. Therefore, even if one HDD 52A₂ breaks down and the storage unit51 ₂ is removed, the HDD controller 56A₁ can access the HDD 52A₁provided in the other storage unit 51 ₁, so the HDDs having theredundant configuration can be hot-swapped in the information processingunits 50 ₁ and 50 ₂.

While the first embodiment describes an example in which an HDD can behot-swapped when there are two information processing units (informationprocessing units 50 ₁ and 50 ₂) in one set, it is also possible tohot-swap an HDD when one set consists of three (or four or more)information processing units. An example of such a configuration isdescribed below as a second embodiment.

FIG. 6 is a schematic plan view of the configuration of a computerdevice according to the second embodiment of the present invention. InFIG. 6, like reference numerals designate like parts as those shown inFIG. 1.

A computer device 60 shown in FIG. 6 is a cluster server device (bladeserver device) in which a plurality of card-shaped informationprocessing units 70 ₁, 70 ₂, 70 ₃, . . . can be mounted in the casing21.

The information processing units 70 ₁, 70 ₂, 70 ₃, . . . can be freelyinserted into and removed from slots 22 ₁, 22 ₂, 22 ₃, . . . in thecasing 21.

A back plane 78 is provided inside the casing 21, and is physically andelectrically connected to the information processing units 70 ₁, 70 ₂,70 ₃, . . . via connectors 77 ₁, 77 ₂, 77 ₃, . . . . The back plane 78supplies electrical power to the information processing units 70 ₁, 70₂, 70 ₃, . . . and also provides an interface.

Each of the information processing units 70 ₁, 70 ₂, 70 ₃, . . .includes a server function similar to that of the computer device 10(see FIG. 9).

Three of the information processing units 70 ₁, 70 ₂, 70 ₃, . . . formone set, as shown in FIG. 6.

The information processing unit 70 ₁ includes a storage unit 71 ₁ and aprocessor unit 74 ₁. The storage unit 71 ₁ and the processor unit 74 ₁can be freely mounted and removed via a connector 73 ₁. The storage unit71 ₁ includes an HDD 72A₁, an HDD 72B₁, and an HDD 72C₁, which aremounted on the same circuit board. The processor unit 74 ₁ includes aCPU 75A₁ and an HDD controller 76A₁ that are mounted on the same circuitboard.

The information processing unit 70 ₂ includes a storage unit 71 ₂ and aprocessor unit 74 ₂. The storage unit 71 ₂ and the processor unit 74 ₂can be freely mounted and removed via a connector 73 ₂. The storage unit71 ₂ includes an HDD 72A₂, an HDD 72B₂, and an HDD 72C₂, which aremounted on the same circuit board. The processor unit 74 ₂ includes aCPU 75B₂ and an HDD controller 76B₂ that are mounted on the same circuitboard.

The information processing unit 70 ₃ includes a storage unit 71 ₃ and aprocessor unit 74 ₃. The storage unit 71 ₃ and the processor unit 74 ₃can be freely mounted and removed via a connector 73 ₃. The storage unit71 ₃ includes an HDD 72A₃, an HDD 72B₃, and an HDD 72C₃, which aremounted on the same circuit board. The processor unit 74 ₃ includes aCPU 75C₃ and an HDD controller 76C₃ that are mounted on the same circuitboard.

In the information processing units 70 ₁, 70 ₂, and 70 ₃, componentsrepresented by (A) in FIG. 6 (the HDD 72A₁, the HDD 72A₂, HDD 72A₃, theCPU 75A₁, and the HDD controller 76A₁) form a group A. This group Acorresponds to one computer device 10 (see FIG. 9) having a redundantconfiguration consisting of three HDDs (n+1 redundant configuration).

In group A, the HDD controller 76A₁ controls writing to and reading fromthe HDD 72A₁, the HDD 72A₂, and the HDD 72A₃ which are large-capacitystorage devices that store various types of data handled by the CPU75A₁.

The HDD 72A₁ is connected to the HDD controller 76A₁ via the connector73 ₁. The HDD 72A₂ is connected to the HDD controller 76A₁ via theconnector 73 ₂, the processor unit 74 ₂, the connector 77 ₂, the backplane 78, and the connector 77 ₁.

The HDD 72A₃ is connected to the HDD controller 76A₁ via the connector73 ₃, the processor unit 74 ₃, the connector 77 ₃, the back plane 78,and the connector 77 ₁.

The HDDs 72A₁, 72A₂, and 72A₃ are mounted by dispersion in physicallyseparate storage units (the storage units 71 ₁, 71 ₂, and 71 ₃).

Similarly, components represented by (B) in FIG. 6 (the HDD 72B₁, theHDD 72B₂, the HDD 72B₃, the CPU 75B₂, and the HDD controller 76B₂) forma group B. This group B corresponds to one computer device 10 (see FIG.9) having a redundant configuration consisting of three HDDs (n+1redundant configuration).

In group B, the HDD controller 76B₂ controls writing to and reading fromthe HDD 72B₁, the HDD 72B₂, and the HDD 72B₃, which are large-capacitystorage devices that store various types of data handled by the CPU75B₂.

The HDD 72B₁ is connected to the HDD controller 76B₂ via the connector73 ₁, the processor unit 74 ₁, the connector 77 ₁, the back plane 78,and the connector 77 ₂.

The HDD 72B₂ is connected to the HDD controller 76B₂ via the connector73 ₂. The HDD 72B₃ is connected to the HDD controller 76B₂ via theconnector 73 ₃, the processor unit 74 ₃, the connector 77 ₃, the backplane 78, and the connector 77 ₂.

The HDDs 72B₁, 72B₂, and 72B₃ are mounted by dispersion in physicallyseparate storage units (the storage units 71 ₁, 71 ₂, and 71 ₃).

Similarly, components represented by (C) in FIG. 6 (the HDD 72C₁, theHDD 72C₂, the HDD 72C₃, the CPU 75C₃, and the HDD controller 76C₃) forma group C. This group C corresponds to one computer device 10 (see FIG.9) having a redundant configuration consisting of three HDDs (n+1redundant configuration).

In group C, the HDD controller 76C₃ controls writing to and reading fromthe HDD 72C₁, the HDD 72C₂, and the HDD 72C₃ which are large-capacitystorage devices that store various types of data handled by the CPU75C₃.

The HDD 72C₁ is connected to the HDD controller 76C₃ via the connector73 ₁, the processor unit 74 ₁, the connector 77 ₁, the back plane 78,and the connector 77 ₃.

The HDD 72C₂ is connected to the HDD controller 76C₃ via the connector73 ₂, the processor unit 74 ₂, the connector 77 ₂, the back plane 78,and the connector 77 ₃. The HDD 72C₃ is connected to the HDD controller76C₃ via the connector 73 ₃.

The HDDs 72C₁, 72C₂, and 72C₃ are mounted by dispersion in physicallyseparate storage units (the storage units 71 ₁, 71 ₂, and 71 ₃).

A hot-swap method according to the second embodiment will be explainedwith reference to FIGS. 6 to 8. An example in which the HDD 72A₂ breaksdown and is hot-swapped without terminating the operation of theinformation processing units 70 ₁, 70 ₂, and 70 ₃ as shown in FIG. 6will be explained.

In FIG. 6, when the HDD 72A₂ of the storage unit 71 ₂ in group A breaksdown, data is recovered from another HDD 72A₁ (or HDD 72A₃) having theredundant configuration, thereby enabling continuous operation.

In group A, the HDD 72A₂ is hot-swapped due to breakdown. As shown inFIG. 7, the storage unit 71 ₂ is removed as a whole and separated fromthe processor unit 74 ₂.

In group A, the HDD 72A₁ (or HDD 72A₃) is currently used and is accessedby the CPU 75A₁ and the HDD controller 76A₁, whereby operation continueswithout being affected by the hot-swap.

Similarly, in group B, the HDD 72B₁ (or HDD 72B₃) is currently used andis accessed by the CPU 75B₂ and the HDD controller 76B₂, wherebyoperation continues without being affected by the hot-swap.

Similarly, in group C, the HDD 72C₁ (or HDD 72C₃) is currently used andis accessed by the CPU 75C₃ and the HDD controller 76C₃, wherebyoperation continues without being affected by the hot-swap.

In the disconnected storage unit 71 ₂, the broken HDD 72A₂ is replacedwith a replacement HDD 72A₂′.

As shown in FIG. 8, after this replacement, the storage unit 71 ₂ ismounted in the processor unit 74 ₂ via the connector 73 ₂. This restoresthe computer device 60 to its original state before breakdown.

As described above, the second embodiment achieves the same effects asthe first embodiment.

Although the first and the second embodiments of the present inventionhave been explained in detail with reference to the accompanyingdrawings, specific configurational examples are not limited to theembodiments, and any design changes or the like to the embodiments areintended to be embraced in the present invention without departing fromthe scope of the invention.

As explained above, according to the present invention, a plurality ofstorage devices having a redundant configuration are mounted by physicaldispersion in a plurality of information processing units. Therefore,even if an information processing unit is removed when one of itsstorage devices breaks down, a controller can access a storage devicemounted in another information processing unit, and the storage devicehaving the redundant configuration can be hot-swapped in the informationprocessing units.

According to the present invention, a plurality of storage deviceshaving a redundant configuration are mounted by physical dispersion in aplurality of freely removable storage units that form a part of aplurality of information processing units. Therefore, even if one of thestorage devices breaks down and the storage unit is removed, acontroller can access a storage device mounted in another storage unit,thereby enabling the storage device having the redundant configurationto be hot-swapped in the information processing units.

According to the present invention, a storage device having a redundantconfiguration can be hot-swapped in a server having a plurality ofinformation processing units.

According to the present invention, a storage device can be hot-swappedin case of breakdown.

Although the invention has been described with respect to a specificembodiment for a complete and clear disclosure, the appended claims arenot to be thus limited but are to be construed as embodying allmodifications and alternative constructions that may occur to oneskilled in the art that fairly fall within the basic teaching herein setforth.

1. A computer device comprising: a plurality of information processingunits configured to execute respective information processing functionsand each having at least one removable storage unit; a plurality ofstorage devices physically dispersed in each of the at least one storageunit provided in the information processing units, said storage devicesbeing capable of hot-swapping without terminating the operation of theinformation processing units, and having a redundant configuration,wherein each information processing unit includes at least two storagedevices; and a plurality of controllers configured to access the storagedevices, wherein: the information processing units are grouped intosets; a number of information processing units in one set is equal to anumber of storage devices accessible to each of the controllers withinone set; and in each set, each of the controllers is mounted on each ofthe information processing units, and accesses only one of the pluralityof storage devices within each of the information processing unitsincluded in the set.
 2. The computer device according to claim 1,wherein the storage devices are removable, the information processingunits include at least a first information processing unit and a secondinformation processing unit, and when a storage device in the firstinformation processing unit is unusable, the controller uses a storagedevice in the second information processing unit.
 3. The computer deviceaccording to claim 1, wherein the information processing unit functionsas a server.
 4. A computer device comprising: a plurality of informationprocessing units configured to execute respective information processingfunctions; a plurality of storage units arranged in the informationprocessing units, and that are removable, wherein one informationprocessing unit includes one storage unit; a plurality of storagedevices physically dispersed in the storage units and having a redundantconfiguration, said storage devices being capable of hot-swappingwithout terminating the operation of the information processing units,wherein one storage unit includes at least two storage devices; and aplurality of controllers configured to be installed in the informationprocessing units and to access the storage devices, wherein eachinformation processing unit includes one of the controllers, wherein theinformation processing units are grouped into sets, and a number ofinformation processing units in one set is equal to a number of storagedevices accessible to each of the controllers.
 5. The computer deviceaccording to claim 4, wherein the storage devices are removable, theinformation processing units include at least a first informationprocessing unit and a second information processing unit, and when astorage device in a first information processing unit is unusable, thecontroller in the first information processing unit uses a storagedevice in the second information processing unit.
 6. The computer deviceaccording to claim 4, wherein the information processing unit functionsas a server.
 7. A cluster server device comprising: a plurality ofinformation processing units, each capable of functioning as a serverand each having at least one removable storage unit; a plurality ofstorage devices physically dispersed in each of the at least one storageunit provided in the information processing units, said storage devicesbeing capable of hot-swapping without terminating the operation of theinformation processing units, and having a redundant configuration,wherein each information processing unit includes at least two storagedevices; and a plurality of controllers configured to access the storagedevices, wherein the information processing units are grouped into sets,and a number of information processing units in one set is equal to anumber of storage devices accessible to each of the controllers withinone set, each of which is mounted on each of the information processingunits, and accesses only one of the plurality of storage devices withineach of the information processing units included in the set.
 8. Thecluster server device according to claim 7, wherein the informationprocessing units include at least a first information processing unitand a second information processing unit, and when one of the storagedevices in the first information processing unit is unusable, thecontroller uses another one of the storage devices in the secondinformation processing unit.
 9. A cluster server device comprising: aplurality of information processing units, each capable of functioningas a server; a plurality of storage units arranged in the informationprocessing units, and that are removable, wherein one informationprocessing unit includes one storage unit; a plurality of storagedevices physically dispersed in the storage units, said storage devicesbeing capable of hot-swapping without terminating the operation of theinformation processing units, and having a redundant configuration,wherein one storage unit includes at least two storage devices; and aplurality of controllers configured to be installed in the informationprocessing units, and to access the storage devices, wherein eachinformation processing unit includes one of the controllers, wherein theinformation processing units are grouped into sets, and a number ofinformation processing units in one set is equal to a number of storagedevices accessible to each of the controllers.
 10. The cluster serverdevice according to claim 9, wherein the storage devices are removable,the information processing units include at least a first informationprocessing unit and a second information processing unit, and when astorage device in a first information processing unit is unusable, thecontroller in the first information processing unit uses a storagedevice in the second information processing unit.
 11. An informationprocessing device comprising: a plurality of processing units eachincluding a processor, a storage controller, and at least one removablestorage unit, wherein the at least one removable storage unit isdetachably connected to the processing unit, and includes a plurality ofstorage devices, said storage devices having redundant configuration andbeing capable of hot-swapping without terminating the operation of theinformation processing unit; and a back plane to which each of theprocessing units is detachably connected, wherein the informationprocessing units are grouped into sets, and a number of informationprocessing units in one set is equal to a number of storage devicesaccessible to each of the controllers within one set, each of which ismounted on each of the information processing units, and accesses onlyone of the plurality of storage devices within each of the informationprocessing units included in the set.
 12. A computer device, comprising:a backplane unit; and a plurality of information processing units eachconnected to the backplane unit, each of the information processingunits, including: a processor unit, a storage unit attached to theprocessor unit in a removable manner, a plurality of storage devicescontained in the storage unit, and a controller mounted on the processorunit that is connected to and controls access to at least one of thestorage devices in a storage unit attached to the processor unit inwhich the controller is mounted, and to at least one of the storagedevices in a storage unit attached to the other processing unit throughthe backplane, respectively, wherein the information processing unitsare grouped into sets, and a number of information processing units inone set is equal to a number of storage devices accessible to each ofthe controllers within one set, each of which is mounted on each of theinformation processing units, and accesses only one of the plurality ofstorage devices within each of the information processing units includedin the set.
 13. The computer device according to claim 12, wherein eachof the storage devices contained in the same storage unit is connectedto the controller mounted in the different processor units,respectively.
 14. A computer device, comprising: a plurality ofprocessing units connected to each other; a plurality of storage units,each of the storage units is connected to one of the processing units ina removable manner, and contains a plurality of storage devices,respectively; and a plurality of controllers, each of the controllers ismounted on corresponding processing units respectively, and isconfigured to control an access to the storage devices, wherein astorage device contained in one of the storage units forms a redundantgroup with a storage device contained in the other storage unit, and thestorage devices forming the redundant group are connected to, and arecontrolled by, the single controller that is mounted on one of theprocessor units, wherein the processing units are grouped into sets, anda number of processing units in one set is equal to a number of storagedevices accessible to each of the controllers within one set, each ofwhich is mounted on each of the processing units, and accesses only oneof the plurality of storage devices within each of the processing unitsincluded in the set.
 15. A cluster service device, comprising: aplurality of information processing units connected to each other, eachof the information processing units is capable of functioning as aserver, and contains a controller that is configured to control anaccess to storage devices respectively; and a plurality of storageunits, each of the storage units is connected to one of the processingunits in a removable manner, and contains a plurality of storage devicesrespectively, wherein, a storage device contained in one of the storageunits forms a redundant group with a storage device contained in theother storage unit, and the storage devices forming the redundant groupare connected to, and are controlled by the same controller that ismounted on one of the processor units wherein the information processingunits are grouped into sets, and a number of information processingunits in one set is equal to a number of storage devices accessible toeach of the controllers within one set, each of which is mounted on eachof the information processing units, and accesses only one of theplurality of storage devices within each of the information processingunits included in the set.